Sperm production is declining faster than thought


European Union


Research of human sperm in a laboratory. Photo AFP, Yuichi Yamazaki

Men’s sperm production worldwide is declining faster than scientists expected. Researchers fear men are approaching a turning point. That would mean the fertility of the majority of men is at risk.

The Dutch news platform Nu.nl was reporting this on Tuesday on the basis of scientific publications. A 2017 study found that sperm cells in Western men dropped by more than 50 per cent in a single ejaculation between 1973 and 2011.

The same researchers looked at what happened in the last ten years. To do this, they examined several studies on sperm between 2014 and 2019. Then they added that data to their old data.

According to the Nu.nl report, the conclusion is that the average sperm concentration between 1973 and 2018 fell from 101 million sperm cells to 49 million sperm cells per millilitre. That is a decrease of 51.6 per cent. And since 2000, that annual decline has been accelerating.

The new data also show that this is not only a European or a Western phenomenon. The research also includes semen samples from men from South and Central America, Africa and Asia. The new study would therefore provide a better global picture than the 2017 analysis.

Global seed crisis

According to lead researcher Hagai Levine at the Hebrew University of Jerusalem, there is a global seed crisis. “We need to address that now before we reach a turning point that may not be reversible,” he says.

Previous studies have shown that fertility is compromised when sperm concentrations fall below 40 million sperm cells per millilitre. Although the average is still above that number according to the latest estimates, eventually, there will be more and more men who will not exceed the 40 million threshold, Levine thinks.

On average, the number of sperm cells per ejaculation is usually between 40 and 300 million per millilitre.


The study also has limitations. For example, the quality of the sperm was not examined. The cause of the decrease has also not been investigated, although various theories exist. One is the increase in chemicals pregnant women pass on to the baby before birth.

Many experts agree that smoking, drinking, obesity and poor nutrition harm sperm production.

World population

Below the article at Nu.nl, there are readers’ comments. Many praise the news since this would lead to a ‘natural decrease’ in the world’s population. Others deny this since the reported phenomenon implies a general decline in men’s health.



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